Related Topics

  Voltage Distribution Over Suspension Insulator | String Efficiency  Type Test and Routine Test of Insulator  Causes of failure of insulator   Insulator in overhead line and types of insulators

Index

SymbolsTransformerRelayPower-SystemBasic-electricalACSR-ConductorCircuit-BreakerInterview-questions-of-Basic-ElectricityInterview-questions-of-transformerInsulatorCurrent-TransformerMCQMCQ-powersystemThermal-power-stationInterview-questions-of-Power-SystemPower-ElectronicsInterview-questions-of-Underground-CableInterview-questions-of-IlluminationIlluminationMCQ-of-ElectronicsMCQ-of-Basic-ElectricalMCQ-of-Transformers MCQ-of-D.C-motor MCQ-of-D.C-generators

Causes of failure of insulator

<< Previous Next >>

 

    The causes of the failure of insulator are :-

  1. Cracking of insulator: The main cause of cracking is due the stress produced in the porcelain due to unequal expansion and construction produced in cement, steel and porcelain caused by seasonal heat cold, dryness, and dampness or by heating of the insulator. To avoid such cracking, many improvements in the designs have been made, sometimes cushions are placed in between shells and steel pins in order to allow for its expansion.
  2. Defective of materials: If the material is defective anywhere, it will puncture from these and thus becomes unfit for further use.
  3. Porosity of the materials: If the porcelain is manufactured at lower temperatures, it will make it porous, and due to this reason it will absorb moisture from air or from cement and thus becomes unfit for further use.
  4. Improper glaze: If material is not properly glazed, the water will stick to it which will result into deposition of dust etc. over it which is partially and reduces the flashover distance. Causes the insulators may be damaged.
  5. Flash over: If there is a flash from one metal part to other, it will cause over-heating and will result into shattering of it.
  6. Mechanical Stress: The pulling of the insulator may also sometimes cause mechanical stress in it ( if its material is defective ) due to which it may break.
  7. Short circuit: The large birds may also sometimes cause arc and thus may result in failure of the insulators (it is possible only if the spacing between the conductors is less).

<< Previous Next >>

 

Related topics :



Recent Post

Multiple Choice Question (MCQ) of Electronics page-17:
241. Which of the following statement is true? a) The saturation voltage VCF of silicon transistor is more than germanium transistor.
b) The saturation voltage VCE for germanium transistor is more than silicon transistor.
c) The saturation voltage VCE for silicon transistor is same as that for germanium.
d) The saturation voltage VCE for silicon transistor is lower than germanium transistor.

Read more...

Multiple Choice Question (MCQ) of Electronics page-16:
226. Which of the following statement is correct? a) Inner electrons are always present in the semiconductor.
b) Bound electrons are always present in the semiconductor.
c) Free electrons are always present in the semiconductor.
d) Inner and bound electrons are always present in the semiconductor.

Read more...

Multiple Choice Question (MCQ) of Electronics page-15:
211. The materials whose electrical conductivity is usually less than 1 × 106 mho/m are a) Semiconductors
b) Conductors
c) Insulators
d) Alloys

Read more...

Multiple Choice Question (MCQ) of Electronics page-14:
196. In which of the following device the base resistors are not added in the package but added externally? a) UJT
b) CUJT
c) PUT
d) None of the above

Read more...

Multiple Choice Question (MCQ) of Electronics page-13:
181. The conduction in JEFT is always by the a) Majority carriers
b) Minority carriers
c) Holes
d) Electrons
e) Holes and electrons simultaneously

Read more...


Name :   

Comments: